Lester Burnham is a 42-year-old advertising executive who is unhappy with his job and his life. He lives with his wife Carolyn, a real estate agent who is also unhappy with their marriage, and their teenage daughter Jane, who is constantly at odds with her parents.
Lester becomes infatuated with his daughter's friend, Angela, who is a cheerleader and a model. He begins to fantasize about her sexually and becomes determined to change his life in order to pursue her.
Lester quits his job and begins to work at a fast food restaurant, much to Carolyn's chagrin. He also begins to work out and take drugs, which causes Carolyn to become even more unhappy.
Meanwhile, Jane begins a relationship with Ricky, the Burnham's new neighbor who is a self-proclaimed "filmmaker" and has a troubled past. Carolyn has an affair with her real estate competitor, Buddy, and begins to spiral out of control.
As the story progresses, the tension between the characters reaches a boiling point, culminating in a tragic event that changes all of their lives forever.
Throughout the movie, Lester narrates his thoughts and feelings, giving the audience insight into his inner turmoil and the disconnection he feels from the world around him. The film also explores themes of beauty, conformity, and the American Dream, as well as the struggles of suburban life and the pressures of society.